title: Torsional resonance mode atomic force microscopy in liquid with Lorentz force actuation.
abstract: In this work, we present a design based on Lorentz force induction to excite pure torsional resonances of different types of cantilevers in air as well as in water. To demonstrate the atomic force microscopy imaging capability, the phase-modulation torsional resonance mode is employed to resolve fine features of purple membranes in a buffer solution. Most importantly, force-versus-distance curves using a relatively stiff cantilever can clearly detect the characteristic oscillatory profiles of hydration layers at a water-mica interface, indicating the high force sensitivity of the torsional mode. The high resonance frequencies and high quality-factors for the torsional mode may be of great potential for high-speed and high-sensitivity imaging in aqueous environment.
authors.affiliation: Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of China. yangcw@phys.sinica.edu.tw
authors.forename: Chih-Wen
authors.initials: CW
authors.lastname: Yang
authors.forename: Ren-Feng
authors.initials: RF
authors.lastname: Ding
authors.forename: Shih-Hsiu
authors.initials: SH
authors.lastname: Lai
authors.forename: Hsien-Shun
authors.initials: HS
authors.lastname: Liao
authors.forename: Wei-Chiao
authors.initials: WC
authors.lastname: Lai
authors.forename: Kuang-Yuh
authors.initials: KY
authors.lastname: Huang
authors.forename: Chia-Seng
authors.initials: CS
authors.lastname: Chang
authors.forename: Ing-Shouh
authors.initials: IS
authors.lastname: Hwang